gemini-2.5-flash vs gpt-5.1
Side-by-side comparison of gemini-2.5-flash and gpt-5.1— benchmarks, pricing, context window and capabilities. Both are accessible through Requesty's unified API. gpt-5.1 outperforms gemini-2.5-flash on 11 of 11 shared benchmarks.
gemini-2.5-flash
Input / 1M
$0.30
Output / 1M
$2.50
Context
1.0M
Model ID
google/gemini-2.5-flash
gpt-5.1
Input / 1M
$1.25
Output / 1M
$10.00
Context
400K
Model ID
openai/gpt-5.1
Benchmark comparison
Intelligence Indexreasoning
gemini-2.5-flash27.0%
gpt-5.147.7%
Coding Indexcoding
gemini-2.5-flash22.2%
gpt-5.144.7%
Math Indexmath
gemini-2.5-flash73.3%
gpt-5.194.0%
GPQA Diamondreasoning
gemini-2.5-flash79.0%
gpt-5.187.3%
AIME 2025math
gemini-2.5-flash73.3%
gpt-5.194.0%
LiveCodeBenchcoding
gemini-2.5-flash69.5%
gpt-5.186.8%
Terminal-Bench Hardagentic
gemini-2.5-flash13.6%
gpt-5.145.5%
τ²-Benchagentic
gemini-2.5-flash31.6%
gpt-5.181.9%
SciCodecoding
gemini-2.5-flash39.4%
gpt-5.143.3%
MMLU Proknowledge
gemini-2.5-flash83.2%
gpt-5.187.0%
Humanity's Last Examreasoning
gemini-2.5-flash11.1%
gpt-5.126.5%
Scores sourced from official model cards, Artificial Analysis, and public leaderboards. Benchmarks measure specific skills and don't capture every aspect of model quality.
Pricing & specifications
| gemini-2.5-flash | gpt-5.1 | |
|---|---|---|
| Input price / 1M | $0.30 | $1.25 |
| Output price / 1M | $2.50 | $10.00 |
| Context window | 1.0M tokens | 400K tokens |
| Max output | 66K tokens | 128K tokens |
| Vision input | Yes | Yes |
| Tool calling | Yes | Yes |
| Reasoning | Yes | Yes |
| Prompt caching | Yes | Yes |
| Computer use | — | — |
| Provider | Google LLC (Gemini API) | OpenAI Inc. |
Questions people ask
Is gemini-2.5-flash better than gpt-5.1?
gpt-5.1 outperforms gemini-2.5-flash on 11 of 11 shared benchmarks. See the benchmark comparison above for specifics — gemini-2.5-flash and gpt-5.1 have different strengths across reasoning, coding, math and multimodal tasks.
Which is cheaper — gemini-2.5-flash or gpt-5.1?
gemini-2.5-flash is cheaper. gemini-2.5-flash costs $0.30/$2.50 per 1M input/output tokens, while gpt-5.1 costs $1.25/$10.00.
Can I use gemini-2.5-flash and gpt-5.1 through the same API?
Yes. Requesty provides a single OpenAI-compatible API that routes to both. Change just the "model" parameter to switch — "google/gemini-2.5-flash" or "openai/gpt-5.1" — no other code changes needed.
What are the context windows?
gemini-2.5-flash supports up to 1.0M tokens of context. gpt-5.1 supports up to 400K tokens. Longer context means you can feed larger documents or codebases in a single prompt, though quality often degrades past 128K for most models.
Switch between gemini-2.5-flash and gpt-5.1 with one line of code
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